Blood Cells- Definition and Types with Structure and Functions


Blood is a fluid connective tissue that consists of plasma and formed elements. Plasma is the liquid matrix of blood that contains water, proteins, electrolytes, hormones, and other substances. Formed elements are the cellular components of blood that include red blood cells (RBCs), white blood cells (WBCs), and platelets.

Blood cells are produced in the red bone marrow by a process called hematopoiesis. Hematopoiesis involves the differentiation of pluripotent stem cells into various types of blood cells. The production of blood cells is regulated by various factors such as hormones, cytokines, and feedback mechanisms.

Blood cells have different functions and characteristics depending on their type. RBCs are responsible for transporting oxygen and carbon dioxide between the lungs and the tissues. WBCs are involved in the immune system and protect the body from infections and foreign substances. Platelets are involved in hemostasis and help in blood clotting.

In this article, we will focus on the two main types of blood cells: RBCs and WBCs. We will discuss their structure, function, and classification in detail. We will also learn about the different types of WBCs and their roles in immunity.